1. Field of Invention
This invention relates generally to the interaction with and control of computers or other electronic equipment. For example, the invention can be used in conjunction with electronic light and sound equipment, personal computers or video recording and playback equipment. In particular, the present invention relates to a means of generating command and/or cursor position control through the use of a remote manipulandum. When in operation, the apparatus does not require a dedicated surface or placement in a fixed position, thereby providing an arrangement which is portable and convenient.
2. Prior Art
A typical computer based graphic display unit basically comprises a display screen, a display controller, a data channel and an input device. Computer input devices exist in various forms. For instance, with a standard typewriter-like keyboard, commands are entered by pressing discrete character keys. The commands are then interpreted utilizing corresponding application software. Similarly, a keyboard may be designed to incorporate the use of special function keys which when interpreted through appropriate software, initiate specific actions or cause the computer display cursor to move. Light pens and touch screens permit somewhat more flexible human-computer interactions; however, these devices require the user's hand to be close to the computer display.
The most recent innovations in the field of position cursor devices, includes the use of joysticks, trackball devices, ball-type cursor control assemblies and mouses. A mouse device provides cursor positioning, and some control capabilities through buttons or momentary action switches. Simply described, a mouse consists of a ball and case. In use, the casing is held by the operator to place the ball against a given dedicated surface. Movement of the case will cause the ball to roll on the surface in any desired two-dimensional direction. The main drawback to the mouse device is that it requires a dedicated, relatively flat and unobstructed area to provide control and cursor position information. Other types of mouses, such as those requiring optical reflective surfaces, require special surface materials.
The ball-type cursor control assembly will typically include a relatively freely rotatable control ball supported for rolling movement-in frictional engagement with two or more traction devices in the form of wheels, shafts and the like to rotate said traction devices about a horizontal axis in response to the rolling movement of the control ball. These traction devices are in turn coupled to appropriate signal generating components which provide electrical output signals for controlling the position of the cursor within the field of the video display, typically in terms of Cartesian coordinates.
Joysticks and trackballs provide control and cursor position information without the need for a large dedicated surface area. A joystick is primarily a lever supported by a gimbal mechanism and is tiltable by the operator in any direction of a plane. The direction and angle of the inclination are detected to generate voltages or digital signals representative of the components in the X- and Y-axis directions, respectively. Most joysticks are designed to be placed on a surface, such as a tabletop. The Joystick device is also limited by the pivoting range of the lever.
In its most basic form a trackball device includes a housing containing a plurality of rotatable supports and a ball seated within the supports. A portion of the ball projects through an opening in the housing to allow for manual rotation by an operator. Trackballs have drawbacks both in design and in operation. The axes of rotation of the rotatable supports of the invention are fixed and proper operation of the device requires manufacture of the parts to very exacting tolerances. Also, trackballs have tended to be unduly noisy and have exhibited poor shock and impact resistance. Finally, while neither joysticks nor trackballs require large dedicated surfaces, many graphically oriented software packages require "dragging" actions which entail simultaneously holding down a button and moving the cursor. Such dragging operations are awkward to perform using trackballs and joysticks.
Accordingly, the primary object of the present invention is to provide a computer input apparatus which the user may move about in virtually any dimension while exercising control over the host computer. This flexibility is achieved by means of a physical design which facilitates both hand-held and stationary desktop operations; and by providing electronic support for a plurality of communication modes and control functionality. This invention will also allow the user to perform functions, such as the control of the movement of a cursor on a video display, without the use of a large dedicated surface. Finally, the invention has incorporated many ergonomically advantageous human-computer interactions, such as the creation of a device which can be manipulated by a human user's natural pointing finger to select and control functions of a computer or other apparatus without having to be close to the apparatus being controlled.